1. Field of the Invention
The present disclosure relates to image display apparatuses, and in particular relates to displaying 2D or 3D images utilizing the same.
2. Description of the Related Art
A general 3D image display technology is completed through eyes of a viewer on the basis of stereoscopic vision principles. The human eyes have a distance of 5 cm to 7 cm therebetween, such that the right eye and the left eye will see images with little differences. The phenomenon of the different right eye and left eye images is the so-called binocular parallax. The conventional 3D image display apparatus is designed based on the binocular parallax, thereby only displaying right eye images for a right eye of a viewer, and left eye images for a left eye of the viewer.
Most of the 3D image display methods based on the binocular parallax need a viewer to wear specific devices such as a polarized glass, a red/blue (or green) glass, a shutter glass, or a helmet mounted display. However, the specific devices are inconvenient for viewers. Therefore, naked-eye type 3D image display apparatuses have recently been developed, such that the viewer may see 3D images without wearing any specific device.
When the naked-eye type 3D image display apparatus is designed on the basis of the binocular parallax principle, it is named a parallax and naked-eye type 3D image display device. In this design, a light-shielding element such as a parallax barrier or a grating is located before an array of light sources of a display device (e.g. LCD), wherein the array of the light source alternately transfers left eye images and right eye images. The right eye of the viewer only sees the right eye images, and the left eye of the viewer only sees the left eye images, respectively, through the parallax barrier. As such, the right eye images received by the right eye and the left eye images received by the left eye will be automatically combined by the viewer's brain to form stereoscopic images. However, the naked-eye type 3D image display apparatuses have poorer resolution than the 3D image display apparatuses accompanied with the specific devices (e.g. polarized glass).
Most of the stereoscopic TVs may display 2D images and 3D images, respectively. The glass type 3D image display method has high image resolution, but the naked-eye type 3D image display method will mainly be applied therewith due to its convenience. So far, for present technology, all naked-eye type 3D image display methods have problems such as a low resolution and narrow viewing angles. In other words, the present naked-eye type 3D image display method is insufficient for TV applications. If the advantages of the glass type 3D image display method and the naked-eye type 3D image display method can be combined, a viewer will experience an individual stereoscopic visual experience. For example, the viewer may wear glasses to watch 3D images of high resolution. Alternatively, the viewer may see 2D TV programs without wearing specific glasses. Naked-eye type 3D programs (such as an advertisement) can be inserted between the 2D TV programs, and the TV will switch to a naked-eye 3D type to display the 3D programs, such that the sudden 3D programs may leave a deep impression on viewers.
Accordingly, a novel display device to solve the described problems is called-for.